If they haven't changed, this is how it works at UCSF: They give points for each part of your application including the interview. You are then put on a list. As they meet, they decide to offer acceptance to a certain number of applicants on the top of the list. As more applicants are interviewed, the list gets longer. That also means that if you interviewed a while back, the newer applicants may push you further down. Close to the end of the cycle, after the last interview, there will be another acceptance round. The waitlist is then created. Some may get a decision letter early in the cycle, others will get it very late almost to the end of the cycle. Hope it helps. Good luck!